| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * S390 version |
| 4 | * Copyright IBM Corp. 1999, 2007 |
| 5 | * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), |
| 6 | * Christian Borntraeger (cborntra@de.ibm.com), |
| 7 | */ |
| 8 | |
| 9 | #define KMSG_COMPONENT "cpcmd" |
| 10 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
| 11 | |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/export.h> |
| 14 | #include <linux/slab.h> |
| 15 | #include <linux/spinlock.h> |
| 16 | #include <linux/stddef.h> |
| 17 | #include <linux/string.h> |
| 18 | #include <linux/mm.h> |
| 19 | #include <asm/diag.h> |
| 20 | #include <asm/ebcdic.h> |
| 21 | #include <asm/cpcmd.h> |
| 22 | #include <asm/io.h> |
| 23 | |
| 24 | static DEFINE_SPINLOCK(cpcmd_lock); |
| 25 | static char cpcmd_buf[241]; |
| 26 | |
| 27 | static int diag8_noresponse(int cmdlen) |
| 28 | { |
| 29 | register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf; |
| 30 | register unsigned long reg3 asm ("3") = cmdlen; |
| 31 | |
| 32 | asm volatile( |
| 33 | " diag %1,%0,0x8\n" |
| 34 | : "+d" (reg3) : "d" (reg2) : "cc"); |
| 35 | return reg3; |
| 36 | } |
| 37 | |
| 38 | static int diag8_response(int cmdlen, char *response, int *rlen) |
| 39 | { |
| 40 | unsigned long _cmdlen = cmdlen | 0x40000000L; |
| 41 | unsigned long _rlen = *rlen; |
| 42 | register unsigned long reg2 asm ("2") = (addr_t) cpcmd_buf; |
| 43 | register unsigned long reg3 asm ("3") = (addr_t) response; |
| 44 | register unsigned long reg4 asm ("4") = _cmdlen; |
| 45 | register unsigned long reg5 asm ("5") = _rlen; |
| 46 | |
| 47 | asm volatile( |
| 48 | " diag %2,%0,0x8\n" |
| 49 | " brc 8,1f\n" |
| 50 | " agr %1,%4\n" |
| 51 | "1:\n" |
| 52 | : "+d" (reg4), "+d" (reg5) |
| 53 | : "d" (reg2), "d" (reg3), "d" (*rlen) : "cc"); |
| 54 | *rlen = reg5; |
| 55 | return reg4; |
| 56 | } |
| 57 | |
| 58 | /* |
| 59 | * __cpcmd has some restrictions over cpcmd |
| 60 | * - __cpcmd is unlocked and therefore not SMP-safe |
| 61 | */ |
| 62 | int __cpcmd(const char *cmd, char *response, int rlen, int *response_code) |
| 63 | { |
| 64 | int cmdlen; |
| 65 | int rc; |
| 66 | int response_len; |
| 67 | |
| 68 | cmdlen = strlen(cmd); |
| 69 | BUG_ON(cmdlen > 240); |
| 70 | memcpy(cpcmd_buf, cmd, cmdlen); |
| 71 | ASCEBC(cpcmd_buf, cmdlen); |
| 72 | |
| 73 | diag_stat_inc(DIAG_STAT_X008); |
| 74 | if (response) { |
| 75 | memset(response, 0, rlen); |
| 76 | response_len = rlen; |
| 77 | rc = diag8_response(cmdlen, response, &rlen); |
| 78 | EBCASC(response, response_len); |
| 79 | } else { |
| 80 | rc = diag8_noresponse(cmdlen); |
| 81 | } |
| 82 | if (response_code) |
| 83 | *response_code = rc; |
| 84 | return rlen; |
| 85 | } |
| 86 | EXPORT_SYMBOL(__cpcmd); |
| 87 | |
| 88 | int cpcmd(const char *cmd, char *response, int rlen, int *response_code) |
| 89 | { |
| 90 | unsigned long flags; |
| 91 | char *lowbuf; |
| 92 | int len; |
| 93 | |
| 94 | if (is_vmalloc_or_module_addr(response)) { |
| 95 | lowbuf = kmalloc(rlen, GFP_KERNEL); |
| 96 | if (!lowbuf) { |
| 97 | pr_warn("The cpcmd kernel function failed to allocate a response buffer\n"); |
| 98 | return -ENOMEM; |
| 99 | } |
| 100 | spin_lock_irqsave(&cpcmd_lock, flags); |
| 101 | len = __cpcmd(cmd, lowbuf, rlen, response_code); |
| 102 | spin_unlock_irqrestore(&cpcmd_lock, flags); |
| 103 | memcpy(response, lowbuf, rlen); |
| 104 | kfree(lowbuf); |
| 105 | } else { |
| 106 | spin_lock_irqsave(&cpcmd_lock, flags); |
| 107 | len = __cpcmd(cmd, response, rlen, response_code); |
| 108 | spin_unlock_irqrestore(&cpcmd_lock, flags); |
| 109 | } |
| 110 | return len; |
| 111 | } |
| 112 | EXPORT_SYMBOL(cpcmd); |